High-voltage Pulsed Power Engineering, Fall 2018

Introduction to Pulsed Power

Fall, 2018

Kyoung-Jae Chung

Department of Nuclear Engineering Seoul National University Introduction

 Pulsed power technology is an area of interest to physicists and engineers in fields requiring high voltages and large currents.  Modern pulsed power runs the gamut from its historical roots in flash radiography, X-ray generation, and the simulation of weapons effects, such as nuclear electromagnetic pulse (EMP), to packaged pulsed power for directed weapons and biological and medical applications. New applications and techniques continue to emerge.

 References  J. Lehr and P. Ron, Foundations of Pulsed Power Technology, IEEE Press (2017).  P. W. Smith, Transient Electronics: Pulsed Circuit Technology, John Wiley and Sons (2002).  H. Bluhm, Pulsed Power Systems: Principles and Applications, Springer (2006).  S. T. Pai and Qi Zhang, Introduction to High Power Pulse Technology, World Scientific (1995).  G. A. Mesyats, Pulsed Power, Springer (2005).  F. T. Ulaby and U. Ravaioli, Fundamentals of Applied Electromagnetics, Pearson (2015).

2/30 High-voltage Pulsed Power Engineering, Fall 2018 : energy compression in space

Heat / Energy

 Generation of spatial region where energy state is higher than surroundings (, processing chamber, plasma jet)  Generation of energetic particles, chemically active species  Energy confinement (compression) in space

3/30 High-voltage Pulsed Power Engineering, Fall 2018 Pulsed power: energy compression in time

 Pulsed Power Technology: the storage of electrical energy over a relatively long time scale and its release in a short duration to create very high power level

 Example: E = 1 kW x 1 sec = 1 kJ P = 1 kJ / 1 us = 1 GW

4/30 High-voltage Pulsed Power Engineering, Fall 2018 Features of pulsed power

 Pulsed power is a scheme where stored energy is discharged as electrical energy into a load in a single short pulse or as short pulses with a controllable repetition rate.

High Power (大電力)  Short rise time  Short pulse width  Focusing of high power in a narrow space

 Generation of high voltage and current  New application of electromagnetic energy

5/30 High-voltage Pulsed Power Engineering, Fall 2018 Features of pulsed power

 Pulsed power is a special power conditioning technique that transforms the characteristics of the prime energy source to the electrical requirements of the load.  Energy from a primary source is accumulated over a relatively long time scale and compressed into pulses of high instantaneous power.  Several stages may be needed to fully exploit the time dependence of breakdown of insulating materials to deliver energy with the required time dependence and amplitude for the application.  The resulting peak power delivered to the load has a large ratio of instantaneous-to-average power.

6/30 High-voltage Pulsed Power Engineering, Fall 2018 Pulse shape parameters

7/30 High-voltage Pulsed Power Engineering, Fall 2018 Typical waveform of repetitive pulses

( ) = + 𝑇𝑇𝑜𝑜𝑜𝑜 𝐷𝐷 𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑇𝑇𝑜𝑜𝑜𝑜 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜 8/30 High-voltage Pulsed Power Engineering, Fall 2018 RF pulse

9/30 High-voltage Pulsed Power Engineering, Fall 2018 Generation of high power pulses

10/30 High-voltage Pulsed Power Engineering, Fall 2018 Typical pulsed power systems

 Capacitive

 Inductive

11/30 High-voltage Pulsed Power Engineering, Fall 2018 Applications of pulsed power

 High Energy Density Plasma  plasma, X-ray generation, plasma  High Power Pulse  Solid state laser (Nd:YAG), Gas laser (Excimer, CO2, Nitrogen)  Particle Beam Generation & Application  Electron (Ion) acceleration, Material processing, Surface treatment  Electromagnetic Acceleration  Rail gun (EM gun), Electrothermal chemical gun (ETC gun),  Electromagnetic Wave Generation  High power microwave (HPM), Electromagnetic pulse (EMP)

12/30 High-voltage Pulsed Power Engineering, Fall 2018 Applications of pulsed power

 Industrial applications  Metal shaping (complex geometries)  Nano-sized particle fabrication  Rock blasting (at construction site)  Exhaust gas treatment  Thermal power plant (electric dust collector)  Waste water treatment (organic matter decomposition)  Ballast water treatment

13/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Lightning vs Pikachu

14/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 High energy density plasmas (HEDP)

Z-pinch plasma MIF Plasma focus

Spheromak formation Plasma thruster Pulsed IEC

15/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Z machine (SNL) : X-ray generator

 The Z Pulsed Power Facility, informally known as the Z machine, is the largest high frequency electromagnetic wave generator in the world and is designed to test materials in conditions of extreme and pressure. Since its refurbishment in October 1996, it has been used primarily as an inertial confinement fusion (ICF) research facility.

16/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 WDM (Warm dense matter) or HEDP research

Warm dense matter research Intense X-ray generation by using wire explosion pulsed X-pinch

Shadowgraphy image of exploding wire

Wide-range EOS model Exp. vs model Electrical conductivity and wire temperature measurements

= ( , ) K. J. Chung et al., J. Appl. Phys. 120, 203301 (2016) 𝜎𝜎 𝜎𝜎 𝜌𝜌 𝑇𝑇 17/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Pulsed ion beam  pulsed D-D beam-target fusion source Pulsed D-D neutron source Compact, sealed-type D-D (104 / 10 us) neutron generator

• 150 keV, 500 mA pulsed D+ beam

+ TiD2 target Ion source D

8x104 n/pulse • Process for metal-hydride reservoir & target Sealed-off

0 Vc = 3.6kV + -20 D -40 Ion source

-60

Output pulse [kV] -80

-100

0 10 20 30 40 50 60 Time [µs]

D2 gas reservoir (Zr powder) TiD2 target

18/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Beam-plasma target fusion proton source  If we increase the electron temperature of target plasma by mirror-confinement, the slowing down time of the injected particle is greatly increased, increasing beam-target interaction probability.

 Neutron production is possible if D2 gas is used as a target.  BNCT

RF (13.56 MHz) Ion source Accelerator Neutralizer D2 gas Coil

Pump D0 beam Al foil

MW (2.45 GHz) D + 3He  p + 4He p + 18O  n + 18F

Plasma Proton (14.7 MeV) 3 He gas Whole-body PET scan using 18F-FDG

19/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Fusion (MCF vs. ICF)

20/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 VEST TF Coils

Partial Solenoid

Breakdown

Vacuum by Partial Solenoid Chamber

Partial Solenoid Plasma Merging

Breakdown by Partial Solenoid

21/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Laser fusion

NIF aims to create a single 500 Laser terawatt (TW) flash of light that reaches the target from numerous directions at the same time, within a few picoseconds. The design uses 192 individual "beamlets", which are amplified in 48 beamlines containing 16 laser amplifiers per line, each one Target chamber amplifying four of the beamlets.

22/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Railgun

23/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Coilgun

A coilgun is a type of projectile accelerator that consists of one or more coils used as electromagnets in the configuration of a synchronous linear motor which accelerate a magnetic projectile to high velocity.

24/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 ETC (Electro-thermal Chemical) gun

25/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 High Power Microwave or EMP

26/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 EM forming

27/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 EM blasting

o.o3 m3 concrete block

28/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Underwater shockwave generation

처리 전 처리 후

10kV/5mm  수중 초음파 발생기  슬러지 처리  지하수 관정 세정 기술 상용화(지하수 관정 세정 기술)  녹조 제거 지반 강화 정경재 외, 대한지질공학회지 23, 29 (2013)  K. J. Chung et al., Contrib. Plasma Phys. 53, 330 (2013)  암반 파쇄 K. J. Chung et al., Curr. Appl. Phys. 15, 977 (2015) S. G. Lee et al., J. Korean Phys. Soc. 66, 1845 (2015) K. Lee et al., J. Appl. Phys. 121, 243302 (2017) K. Lee et al., Appl. Phys. Lett. 112, 134101 (2018) 29/30 High-voltage Pulsed Power Engineering, Fall 2018 Examples of pulsed power

 Water-bloom removal Gas vesicles

w/o pulse w/ pulse

w/o pulse w/ pulse

 Shock wave destroys gas vesicles to sink the water-bloom down to the bottom

 NOx removal 40 kV, 4 MW, 0.15 J/pulse, 100 Hz  20% reduction of NOx with 15 W

30/30 High-voltage Pulsed Power Engineering, Fall 2018